Elastic fluid turbine



Dec. 11, 1945. D. J. BLOOMBERG 2,390,772

ELASTIC FLUID TURBINE Filed Jan. 25, 1945 Inventor: David J. Bloombevg, by 1924 7 J His Attorney.

Patented Dec. 11, 1945 ELASTIC FLUID TURBINE David J. Bloomberg, Newton, Mass, assignor to General Electric Company,

New York a corporation of Application January 25, 1943, Serial No. 473,455

4 Claims. (01. 253-'70) The present invention relates to elastic fluid turbines comprising a forward section for operation in one direction of rotation and a reversing section for operation in the opposite direction of rotation such as are used, for example, in ship propulsion arrangements to drive a ship in for- Ward and reverse directions. More particularly,

.the invention relates to the kind of turbines in which the discharge sides of the forward and reversing turbine sections face each other and exhaust into a common exhaust casing or hood. Various constructions have heretofore been devised to deflect elastic fluid discharged from either the forward or the reversing section into the common exhaust casing to prevent fluid discharged from one section from entering the other section. I

The object of my invention is to provide an improved construction and arrangement of turbines whereby elastic fluid discharged from the ahead and reversing sections of such turbine is effectively and efliciently turned outward into a common exhaust casing.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawing,

In the drawing Fig. 1 illustrates a section of an elastic fluid turbine embodying my invention, and Fig. 2 is a perspective view of certain parts of Fig. 1.

The turbine in the present example comprises a casing I which has an exhaust section or hood II for receiving exhaust fluid and conducting it through an opening I2 to a condenser or the like. A rotor I3 is disposed within the casing and includes a forward section with a plurality of bucket wheels I4 and a reversing section with a plurality of bucket wheels I5. The elastic fluid on its path through the bucket wheels I4 of the forward section is guided by diaphragms I6 interposed between successive bucket wheels and supported on the casing ID. A similar diaphragm I1 is interposed between the two bucket wheels I of the reversing section. Elastic fluid is conducted to the first stage wheel I5 of the reversing section from a, chest I 8 by means of a stationary nozzle section I9. The last stage bucket wheels, I4, I5, of the two sections face each other and are arranged to discharge through an annular outlet opening in the turbine easing into the exhaust hood I I. In order to prevent elastic fluid discharged from either section from being forced axially against the discharge side of the other section I provide improved means for radially deflecting elastic fluid discharged from both sections. This means in the present example comprises a plurality of circumferentially spaced, fluid directing baffles 2| which have inner edges secured to a cylindrical ring 22 concentrically spaced from the turbine shaft and an outer portion secured to a ring 23 supported on the turbine casing by a weld 24. These vanes may have any desirable shape and curvature. In the present instance they are flat and each is inclined by about 45 degrees towards a radial plane through the center of the turbine and the inner edge of the vane.

As indicated by arrows in Fig. 2, with this arrangement elastic fluid discharged from the bucket passages of the last turbine stage I4 of the ahead section is deflected radially outward towards the opening or outlet 20 into the exhaust hood I I. In order to render the same baflles 2I effective with regard to elastic fluid discharged from the reversing section, a plurality of circumferentially spaced stationary guide vanes 25 are supported in the casing II] between the baffles ZI and the last stage wheel I5 of the reversing section. The vanes 25 reverse the direction of fluid discharged from the last bucket wheel I5 and direct the fluid with an appreciable tangential component towards the baffles 2|, as is also indicated by the arrows in Fig. 2.

Thus, with my arrangement elastic fluid discharged from the last stage bucket wheels of the ahead and reversing sections of a reversing turbine is effectively turned outward into a common exhaust hood or casing. The bafiies and guide vanes are entirely supported on the casing. Therefore, they do not increase the mass of the turbine rotor. Moreover, the arrangement as described above permits comparatively close spacing of the last stage wheel of the ahead and reversing sections, resulting in a compact and economical construction.

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I wish to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Elastic fluid turbine comprising a casing defining an exhaust hood, a rotor disposed in the casing and including a forward section with a plurality of bucket wheels and a reversing section with a bucket wheel having a discharge side facing the discharge side of the forward section, and means for directing elastic fluid discharged from the reversing and the ahead sections into said exhaust hood comprising a plurality of circumferentially spaced substantially flat baflles supported in the casing, each bafiie being arranged at an angle of about 45 degrees to a radia1 plane through the center of the turbine and an inner edge of the bafile and a plurality of stationary guide vanes supported in the casing and disposed between the discharge side of one section and said baflies.

2. An elastic fluid turbine comprising a casing, a rotor supported in the casing and having at least one forward bucket wheel and ayreversing bucket wheel, said bucket wheels being arranged on the rotor with their discharge sides facing each other and with a common annular discharge passage defined therebetween, said casing forming an annular exhaust hood in communication circumiierentialiy with said discharge passage, 'a plurality of circumferentially spaced substantially rectangular baffles supported by the casing and arranged in said discharge, passage, :each baffle having its width substantially parallel to the axis of the rotor and its length extending radially outward with an appneciable tangential. component :50 that the baffle :iorms an acute ang le with a radial plane through the axi -.of the rotor so as to deflect fluid bucket wheel radially -outwa-rd into the exhaust hood, and an annular row of stationary guide vanes supported in the casing between said bailies and the other bucket wheel and arranged to cause discharged from-said-other bucket -1v-heel to impinge on said bafiles with a a-tangential iuelocity component having the same direction as that of :fluid discharged from the first-mentioned buck- ;et wheel. a ,7

3. An elastic fluid turbine comprising a casing, a rotor supported in the casing and havi-ng :at least one vforward bucket wheel and a reversing :bucket =wheel, said bucket wheels being arranged on the rotor with their discharge sides ,iacing each other and with a-common annular :dischange v discharged from 'one rectangular baffles supported by the casing and arranged in said discharge passage, each bafile having its width substantially parallel to the axis of the rotor and its length extending radially outward with an appreciable tangential component so that the baffle forms an acute angle with a radial plane through the axis of the rotor so as to deflect fluid discharged from the forward bucket wheel radially outward into the exhaust hood, and an annular row of stationary guide vanes supported in the casing between said bafiies and the reversing bucket wheel and arranged to cause fluid discharged from the reversing bucket wheel to impinge on said bafiies with a tangential velocity component having the same direction as that of fluid discharged from the forward bucket wheel.

A. An elastic fluid turbine comprising a casing,

:a rotor supported in the casing and having a forward section and :a reverse section with their discharge sides facing each other and a common annular discharge passage defined therebetween, .said casing forming an -annular exhaust hood in communication circumferentially. with said discharge passage, one .of .said sections including an annular row .of stationary guide vanes at its discharge ,end adapted .to direct the elastic fluid into said common discharge passage with a tangential velocity component Off thesame direction as that of the fluid discharged from said other section, and :a .set of cirournierentially spaced inclined :bafiles supported by'sai-d casing and arranged between said two sections and closely adjacent the discharge sides thereof, said ibaffles extending toward said discharge hood and being adapted-to guide and :direct the fluid clischarged from either section into said discharge hood in such a way that the fluid passes over substantially the whole area of said bafles.

'LDAVID J.. BLOQMEERG. 

